<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
       body {
	     background: url('http://csssecrets.io/images/stone-art.jpg');
       }
       div {
         border: 10px solid hsla(0, 0%, 100%, 0.5);
         background: white;
         background-clip: padding-box;

         max-width: 20em;
         padding: 2em;
         margin: 2em auto 0;
         font: 100%/1.5 sans-serif;
       }
    </style>
</head>
<body>
    <div>Can I haz semi-transparent borders? Pretty please?</div>
</body>
</html>